This invention relates to a disposable wearing article such as a disposable diaper adapted to absorb and to contain excretion discharged thereon.
Japanese Patent Application Publication No. 1992-354948A describes a pants-type disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the top- and backsheets, configuring a front waist region and a rear waist region opposed to each other and a crotch region extending between these waist regions so that the front and rear waist regions may be bonded together along side edge portions thereof to form the pants-type disposable diaper defining a waist-opening and a pair of leg-openings.
In the vicinity of a peripheral edge portion of the waist-opening, a substantially liquid-impervious leak-barrier cuff associated with the waist-opening extends in a waist-surrounding direction on the side of outer surface of the topsheet. The leak-barrier cuff has a first cuff extending in the waist-surrounding direction across the front waist region and a second cuff extending in the waist-surrounding direction across the rear waist region. The first cuff has a dimension approximately equal to one half of a wearer""s waist size and the second cuff has a dimension approximately equal to the other half of the wearer""s waist size.
The cuff comprising these two cuff-halves has a fixed end portion lying adjacent the peripheral edge portion of the waist-opening and bonded to the diaper, a free end portions extending from the fixed end portion toward the crotch region and fixed lateral end portions lying on the transversely opposite side edge portion of the front and rear waist regions and bonded to the diaper. The free end portion is provided with an elastic member being stretchable in the waist-surrounding direction and bonded under tension to the free end portion. The free end portion of the cuff is normally biased under contractile force of the elastic member to rise on the topsheet and thereby to form a barrier against excretion.
Of the leak-barrier cuff, the free end portion extending in the waist-surrounding direction between the fixed lateral end portions are not bonded to the diaper, so the free end portions may often be turned up as the diaper worn is vertically moved along the wearer""s waist. Having been turned up, the leak-barrier cuff no more functions as the barrier against excretion and consequently excretion may leak out beyond the peripheral edge portions of the waist-opening.
It is an object of this invention to provide a disposable wearing article improved so that the free end portion of the leak-barrier cuff associated with the waist-opening is not easily turned up and reliably functions as the barrier against leak of excretion.
According to this invention, there is provided a disposable wearing article comprising a liquid-pervious topsheet, a liquid-impervious backsheet, a liquid-absorbent core, configuring a front waist region, a rear waist region and a crotch region extending between the front and rear waist regions, longitudinally opposite end portions extending in a first direction across the front and rear waist regions, respectively, transversely opposite side edge portions extending between the longitudinally opposite end portions in a second direction, and a substantially liquid-impervious leak-barrier cuff associated with a waist-opening lying on an outer surface of the topsheet and extending in the first direction across at least one of the front and rear waist regions.
The disposable wearing article further comprises the leak-barrier cuff which has a fixed end portion lying adjacent one longitudinal end portion of the article, a free end portion extending from the fixed end portion toward the crotch region and fixed lateral end portions lying on the side edge portions and bonded to the article wherein elastic member being stretchable in the first direction is attached under tension to the free end portion, normally biasing the free end portion to rise on the topsheet and the free end portion has at least one retaining zone in which the free end portion is bonded to the article.
According to one embodiment of this invention, the core has transversely opposite side edges extending in the second direction inside the fixed lateral end portions of the leak-barrier cuff and the retaining zone is defined between the fixed side portion of the cuff and adjacent the side edge of the core.
According to another embodiment of this invention, the free end portion defines a free edge extending in the first direction so as to describe a circular arc which is convex toward the longitudinal end portion of the article.